This chapter argues that the organizational structure of the Argentine teachers’ confederation (CTERA), with power rooted in provincial and municipal actors, is crucial for explaining why teachers engaged in ongoing protests. It examines the process of union rebuilding in the wake of democratization, after harsh repression during the military regime. Even if newly elected leaders offered little support to the union because of the debt crisis, union leaders made some progress in consolidating CTERA through their own initiatives. The chapter then turns to decentralization under President Carlos Menem as a point of inflection. This undermined national union leaders, weakening their hold on the base. Once organizational hierarchies were weakened, movementism became the union’s political strategy.